Slag Hill is a subglacial volcano associated with the

Mount Cayley volcanic field The Mount Cayley volcanic field (MCVF) is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. It consists of glassy, augite-phyric

basaltic andesite Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central Amer ...

in steep-sided, glassy, finely jointed domes and one small, flat-topped

bluff Bluff or The Bluff may refer to: Places Australia * Bluff, Queensland, Australia, a town * The Bluff, Queensland (Ipswich), a rural locality in the city of Ipswich * The Bluff, Queensland (Toowoomba Region), a rural locality * Bluff River (New ...

. The finely jointed domes are similar to those of

Ember Ridge Ember Ridge is a volcanic mountain ridge associated with the Mount Cayley volcanic field in British Columbia, Canada. Ember Ridge is made of a series of steep-sided domes of glassy, complexly jointed, hornblende-phyric basalt with the most recent e ...

. There are quench features at Slag Hill, which is suggesting that the volcanic activity was subglacial. Slag Hill was formed throughout the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

period, but its most recent volcanic activity produced a lava flow on its western lobe that shows no evidence of ice-contact volcanism.Catalogue of Canadian Volcanoes
Retrieved on 2007-05-28 This indicates the lava flow was erupted less than 10,000 years ago after the last glacial period.

References

See also